Tom Kha Gai

Tom kha gai is chicken simmered in coconut milk with galangal, lemongrass and kaffir lime leaf. It shares its aromatics almost exactly with tom yum goong, but the coconut milk it's built on softens the sourness into something rounder and gentler.

What it really is

Galangal, lemongrass and kaffir lime leaf infuse into simmering coconut milk the same way they would for a clear tom yum broth, but here the coconut milk is the base itself rather than an optional addition, coating every spoonful in richness that mellows the chilli and lime that follow. Chicken poaches gently in that broth until tender, and the soup finishes with a squeeze of lime and fish sauce rather than the harder, sharper sourness tom yum is known for.

The coconut milk changes the entire character of the soup, not just its texture. Swap it out and the broth reads as a plain herbal chicken soup missing its point; tom kha gai's balance depends on that richness softening the sour-hot edges the aromatics would otherwise deliver on their own.

How it is served

• In a bowl, whole pieces of galangal and lemongrass often left in for aroma rather than eaten.
• With steamed rice on the side.
• As a starter, alongside sharper dishes on the same table.

How to write it on the menu

• Flag the fish sauce.
• Say it's milder than tom yum, since guests often assume all Thai soups carry the same sharp heat.
• Note that the galangal and lemongrass pieces are for aroma, not eating, since new guests sometimes bite into them by mistake.